After pondering on this for a while, I have concluded that I am bi. This is the first time I've really been open about this sort of thing, and I'm glad I've finally typed this.
I do hope this doesn't get somehow circulated around my school year; I think that's the worst possible scenario.
I don't really care whether anyone is gay/straight/bi/whatever you are, so long as you're a pleasant person to be around and not an insolent moron.